PT exercise question

Hi,

I'm doing some PT to build core strength.

One of these exercises involves lying on your back, knees bent. Then to raise your back so that your thighs line up with your back in a straight line, so your body basically forms a diagonal line from the knees to the shoulders, and then to hold this pose for 3 seconds.

I think this is called the bridge but I'm not sure.

What are your comments about this exercise,

thanks